The Emperor 280 is a compact (9.375" wide), single Bio-Wheel version of the Emperor Filtration System. And, because it's an Emperor, it's packed with the same one-of-a-kind Emperor design features-flow rate efficiency unmatched by other filters in its class, a cartridge with twice the activated carbon filtration capacity, a media container to hold an additional four ounces of filter media, and superior wet/dry spray bar-driven Bio-Wheel filtration. The Emperor 280 features not one pump (as in ordinary power filters), but two separate water pumps. The Flow Pump directs water through the entire multi-stage filtration system at a certified rate of 280 gallons per hour. The Bio-Pump pressurizes and sends a stream of prefiltered, oxygen-rich water through the spray bar to power-drive the ammonia-fighting Bio-Wheel. The Emperor 280 comes with an adjustable mid-level intake strainer for maximum circulation within your aquarium. A heavy duty Emperor Filter Cartridge provides superior mechanical and chemical filtration-twice the amount of activated carbon filtration and 45% more mechanical filter area than the largest Rite-Size Cartridge. Dense poly fibers trap larger quantities of dirt and unsightly, unhealthy solid waste. Magnum Activated Carbon, the highest grade there is, removes harmful contaminants, odors, and discoloration. A refillable media container holds an additional four total ounces of activated carbon or other chemical filtration media working to maximize pollution removal capacity. An extra large spray bar driven Bio-Wheel delivers classic wet/dry biological filtration. It eliminates toxic ammonia on contact and creates higher oxygen levels, more stable pH, and a healthier environment for fish and plants. In addition, the Emperor 280 is U/L listed. Epoxy-sealed, moisture-proof motor ensures safe operation. It's big tank system technology for the mid-size aquarium. Perfect for marine or freshwater use.